<?php
go(function(){
    $client = new Swoole\Coroutine\Client(SWOOLE_SOCK_UDP);
    $client->connect('127.0.0.1', 8083);

    $client->send(json_encode([
        'action'    =>    'hello',
        'format'    =>    'Y-m-d H:i:s',
    ]));
    var_dump($client->recv());

    $client->send(json_encode([
        'action'    =>    'hello',
        'format'    =>    'c',
    ]));
    var_dump($client->recv());
});